This is a memory test for Dreamcast system RAM, based on public domain code
found here: https://barrgroup.com/embedded-systems/how-to/memory-test-suite-c

This will run on both 16MB and 32MB Dreamcats, but only with this patch applied
to KallistiOS:
https://github.com/tsowell/KallistiOS-scummvm/commit/09aea2bb3becc22dc4f178cf4200164659177c76

Sample output:

KallistiOS Git revision 6830519-dirty:
  Wed 24 Jun 2020 02:04:09 PM AKDT
  tom@localhost.localdomain:/home/tom/dc/release/KallistiOS
maple: active drivers:
    Dreameye (Camera): Camera
    Sound Input Peripheral: Microphone
    PuruPuru (Vibration) Pack: JumpPack
    VMU Driver: Clock, LCD, MemoryCard
    Mouse Driver: Mouse
    Keyboard Driver: Keyboard
    Controller Driver: Controller
    Lightgun: LightGun
  DMA Buffer at ac096520
dc-load console support enabled
base address: 0x8c100000
number of bytes: 32440320
memTestDataBus: PASS
memTestAddressBus: PASS
memTestDevice: PASS
arch: shutting down kernel
maple: final stats -- device count = 0, vbl_cntr = 0, dma_cntr = 0
